CDCR Secretary Matt Cate has said he wants to increase prisoner rehabilitation and that prisons have been so overcrowded that it's been difficult to identify and deliver inmates' needs. (Photo by Kevork Djansezian/Getty Images)
Kevork Djansezian/Getty Images

Much sentencing law rests on a simple premise: people who've committed more than one crime are more likely to reoffend, so they deserve harsher punishment. That concept is at the root of California's Three Strikes law that gives prosecutors and judges one way (among several) to sentence repeat offenders to longer terms.

Under Three Strikes, the courts can double the sentence for anyone who commits a serious or violent felony if he or she commits a new felony, regardless of its severity. A person who commits two serious or violent felonies can be sentenced to 25 years to life in prison for any third felony.

In November, with Proposition 36, California voters will consider a change to the law. Specifically, to receive a sentence of 25-to-life third strikers, as they're called, would have to commit a third serious or violent felony. That means the courts could no longer sentence offenders to life in prison with the possibility of parole for like petty theft and an array of "less serious" crimes. In addition, third strikers in prison on less serious felonies could petition the court for earlier parole hearings.

This change would likely affect about 3,200 current inmates; some activists say more. Many voters who may decide whether to change the law don't know who these third strikers are - or how likely they'd be to continue their criminal behavior if they're released.

New prison data obtained by California Watch and the San Francisco Chronicle sheds some light on this set of prisoners. The organizations examined risk assessments for third strikers versus other felons, and found that:

Third strikers are no more likely than non-strikers to engage in the kind of "criminal thinking" that coorrections officials believe is a good indicator of future criminality;

Third strikers are very likely to have substance abuse issues - 70 percent showed a high need for treatment;

Reporters conclude that substance abuse treatment earlier in life — in and out of prison — could have likely prevented later crimes. They report, the state prison system provides 2,800 inmates a year, far fewer than the number who need it, with substance abuse treatment.